Hypodermic syringes typically have a hollow needle at one end of a cylindrical fluid container and a moveable plunger at the opposite end of the container. The plunger is used to discharge fluid from the cylinder through the needle, or to draw fluid through the needle into the cylinder. The syringe needle should allow for relatively painless entry into the skin. Therefore, the needle may have a relatively small cross section and an extremely sharp tip.
Due to the sharpness of the needle tip, use of the syringe requires great care. Even the most casual contact of the needle with the skin of the health care provider handling the syringe is likely to penetrate the skin, a circumstance commonly known as a "needle stick." Although a needle stick is a minor injury, it carries the threat of transmitting such dangerous diseases as hepatitis and AIDS from the patient receiving an injection to the health care provider. Furthermore, potentially lethal drugs or toxins can also be accidently transmitted by a needle stick.
Due to the sharpness and delicate structure of the syringe needle, a removable protective sheath or cap, usually made of plastic, is installed over the needle. The protective sheath is an elongated sleeve, slightly longer than the needle. The sheath is relatively narrow and protects the needle while permitting safe handling of the syringe when the syringe is not in use. Before using the syringe, the protective sheath must be removed from the needle, a procedure known as uncapping. During uncapping, the sheath is normally gripped between the fingers of one hand, while the other hand holds the cylinder or main body portion of the syringe. After the syringe has been used, the protective sheath is often replaced over the needle, a procedure known as recapping. Unfortunately any distraction, any shake of the hand, and any misalignment of the needle and sheath during recapping is likely to result in a needle stick to the hand which holds the sheath.
Several devices have been constructed to protect against accidental needle sticks. For example, U.S. Pat. No. 4,717,386 to Simmons discloses a safety device for a needle. The device comprises a paddle-shaped member that includes a hand shield section. A handle extends from the hand shield section. A sheath or cap retainer is formed or otherwise provided at a central portion of the hand shield section. The cap retainer includes a recess having a countersink, a reduced mid-portion and a reduced end portion, thus providing stepped edges.
U.S. Pat. No. 4,767,412 to Hymanson discloses a finger guard for use with a storage tube for a hypodermic needle to prevent accidental injury. The finger guard comprises a tubular finger gripping portion having a bore therein in which the storage tube is received. Radially inwardly extending deformable flaps grip the storage tube, whereby differing sizes of storage tube may be accommodated. An annular guard portion extends radially outwardly of the finger grip portion at the forward end of the guard to prevent the needle from contact with the fingers when attempting to insert the needle into the storage tube.
U.S. Pat. No. 4,919,656 to Bracker et al. discloses a safety device for a hypodermic syringe. The device is a rigid plastic disk which bites into and displaces material on the shell portion of a needle cover cap to protect a user from accidental stick injuries while recapping the needle. The disk has a central aperture which is formed of a plurality of radially projecting teeth.
Needle sticks to the hands are a prevalent work site accident in hospitals, physician's offices and medical laboratories. The risk of disease or drug transmission from needle sticks makes it desirable to have a device for uncapping and recapping the protective sheath of a syringe while minimizing the risk of needle sticks to the hands. Such a device should be able to releasably clamp the protective sheath and to exert removal or reattachment pressure thereon. Such a device should also be resilient, simple to handle, and simple to manufacture.